From: Chen Hanxiao <[email protected]> If backend(such as dpdk) lack the feather, don't assume it in vring_enable. Or we may fail in vhost_net_start, then we can't use vhost. This will bring compat issue with old version backend.
Signed-off-by: Chen Hanxiao <[email protected]> --- v2: return 0 there if protocol features aren't negotiated. hw/net/vhost_net.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index f2d49ad..a1b796a 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -425,11 +425,17 @@ int vhost_set_vring_enable(NetClientState *nc, int enable) { VHostNetState *net = get_vhost_net(nc); const VhostOps *vhost_ops = net->dev.vhost_ops; - - nc->vring_enable = enable; + int ret; if (vhost_ops && vhost_ops->vhost_set_vring_enable) { - return vhost_ops->vhost_set_vring_enable(&net->dev, enable); + ret = vhost_ops->vhost_set_vring_enable(&net->dev, enable); + /* + * Try to enable vring feature. + * If protocol features aren't negotiated, return 0 for back compat. + */ + if (ret == 0) { + nc->vring_enable = enable; + } } return 0; -- 1.8.3.1
